The invention relates to a drum-type winder for winding a web of material, especially a web of paper or cardboard, on cores, with a mechanism for inserting a fresh core in the drum valley and for separating the web, whereby a structure that accommodates the core and a mechanism that separates the web are secured to a double-articulation arm that pivots parallel to the axis of a drum.
Drum-type winders are employed in particular to wind webs of paper or cardboard deriving from a supply reel into smaller individual reels, whereby the web from the supply reel is simultaneously slit longitudinally into individual webs. They have two or more drums, and the reels are wound axially adjacent onto cores in the valley between two drums. Once the reels have attained the desired diameter, the longitudinally slit individual webs arriving from the supply reel are separated, the finished reels are unloaded, fresh cores are inserted into the valley, and the newly established initial sections of individual web are wound onto the cores.
A drum-type winder of this general type is known from German AS 2 930 474. It has a perforating rail fastened to a shell segment secured between two bucklers. The shell segment pivots around an eccentric axis that parallels the axis of the drum. Pivoting on the bucklers are arms that support between themselves a trough-shaped accommodation for a fresh core. The arms, and accordingly the trough with the fresh core, can be pivoted in relation to the bucklers until the trough arrives above the nip between the two drums. The web separates by tearing against the perforating structure when the finished reel is ejected from the drum valley. A fresh core is inserted in the valley while the newly established initial web section is secured to the drum.
The drawback to this winder is that the point at which the web is separated cannot be varied. It has been demonstrated that problems in fastening the newly established initial web section to the fresh core can occur when the cores differ in diameter if the length of the initial web section up to the line where the core contacts the drum is not appropriate to the particular core diameter. If the core has a long diameter, the length of the initial web section between the line of separation and the line of contact between the core and the drum must be greater than if the core has a shorter diameter.
One method of adapting the position of the line of separation to cores of different diameter is known from German Patent 3 151 256. That winder has a pivoting subassembly consisting of a stapling and cutting mechanism that travels across the axis of the drum. This solution, however, necessitates a separate pivoting mechanism to insert a fresh core.